Food Allergy : Unproven Theories

by National Institute of Health

(Page 5 of 5)

There are several disorders that are popularly thought by some to be caused by food allergies. There is not enough scientific evidence, or evidence that does exist goes against such claims.

Migraine Headaches

There is controversy about whether migraine headaches can be caused by food allergy. Studies show people who are prone to migraines can have their headaches brought on by histamines and other substances in foods. The more difficult issue is whether food allergies actually cause migraines in such people.

Arthritis

There is virtually no evidence that most rheumatoid arthritis or osteoarthritis can be made worse by foods, despite claims to the contrary.

Allergic Tension Fatigue Syndrome

There is no evidence that food allergies can cause a disorder called the allergic tension fatigue syndrome, in which people are tired, nervous, and may have problems concentrating, or have headaches.

Cerebral Allergy

Cerebral allergy is a term that has been given to people who have trouble concentrating and have headaches as well as other complaints. These symptoms are sometimes blamed on mast cells activated in the brain but no other place in the body. Researchers have found no evidence that such a scenario can happen. Most health experts do not recognize cerebral allergy as a disorder.

Environmental Illness

In a seemingly pristine environment, some people have many non-specific complaints such as problems concentrating or depression. Sometimes this is blamed on small amounts of allergens or toxins in the environment. There is no evidence that such problems are due to food allergies.

Childhood Hyperactivity

Some people believe hyperactivity in children is caused by food allergies. But researchers have found that this behavioral disorder in children is only occasionally associated with food additives, and then only when such additives are consumed in large amounts. There is no evidence that a true food allergy can affect a child's activity except for the possibility that if a child itches and sneezes and wheezes a lot, the child may be uncomfortable and therefore more difficult to guide. Also, children who are on anti-allergy medicines that cause drowsiness may get sleepy in school or at home.

Controversial and Unproven Diagnostic Methods

Cytotoxicity testing One controversial diagnostic technique is cytotoxicity testing, in which a food allergen is added to your blood sample. A technician then examines the sample under the microscope to see if white cells in the blood "die." Scientists have evaluated this technique in several studies and have found it does not effectively diagnose food allergy.

Provocative challenge

Another controversial approach is called sublingual (placed under the tongue) or subcutaneous (injected under the skin) provocative challenge. In this procedure, diluted food allergen is put under your tongue if you feel that your arthritis, for instance, is due to foods. The technician then asks you if the food allergen has made your arthritis symptoms worse. In clinical studies, researchers have not shown that this procedure can effectively diagnose food allergy.

Immune complex assay

An immune complex assay is sometimes done on people suspected of having food allergies to see if groups, or complexes, of certain antibodies connect to the food allergen in the bloodstream. Some think that these immune groups link with food allergies. But the formation of such immune complexes is a normal offshoot of food digestion, and everyone, if tested with a sensitive enough measurement, has them. To date, no one has conclusively shown that this test links with allergies to foods.

IgG subclass assay

Another test is the IgG subclass assay, which looks specifically for certain kinds of IgG antibody. Again, there is no evidence that this diagnoses food allergy.

Controversial and Unproven Treatments

Controversial treatments include putting a diluted solution of a particular food under your tongue about a half hour before you eat the food suspected of causing an allergic reaction. This is an attempt to "neutralize" the subsequent exposure to the food that you believe is harmful. The results of a carefully conducted clinical study show this procedure does not prevent an allergic reaction.

Allergy shots

Another unproven treatment involves getting shots (immunotherapy) containing small quantities of the food extracts to which you are allergic. These shots are given regularly for a long period of time with the aim of "desensitizing" you to the food allergen. Researchers have not yet proven that allergy shots reliably relieve food allergies.

Research

The National Institute of Allergy and Infectious Diseases does research on food allergy and other allergic diseases. This research is focused on understanding what happens to the body during the allergic process - the sequence of events leading to the allergic response and the factors responsible for allergic diseases. This understanding will lead to better methods of diagnosing, preventing, and treating allergic diseases. Researchers also are looking at better ways to study allergic reactions to foods.

One study by the Johns Hopkins Children's Center showed that simply washing your hands with soap and water will remove peanut allergens. Also, most household cleaners will remove them from surfaces such as food preparation areas at home as well as day care facilities and schools. These easy-to-do measures will help prevent peanut allergy reactions in children and adults.

Educating people, including patients, health care providers, school teachers, and day care workers, about the importance of food allergy is also an important research focus. The more people know about the disorder, the better equipped they will be to control food allergies.

About the Author

NIH is the nation's medical research agency - making important medical discoveries that improve health and save lives. The National Institutes of Health (NIH), a part of the U.S. Department of Health and Human Services, is the primary Federal agency for conducting and supporting medical research.